Increased risk of latent tuberculous infection among persons with pre-diabetes and diabetes mellitus

SETTING

Although diabetes mellitus (DM) is an established risk factor for active tuberculosis (TB) disease, little is known about the association between pre-DM, DM, and latent tuberculous infection (LTBI).

OBJECTIVE

To estimate the association between DM and LTBI.

DESIGN

We conducted a cross-sectional study among recently arrived refugees seen at a health clinic in Atlanta, GA, USA, between 2013 and 2014. Patients were screened for DM using glycosylated-hemoglobin (HbA1c), and for LTBI using the QuantiFERON(®)-TB (QFT) test. HbA1c and QFT results, demographic information, and medical history were abstracted from patient charts.

RESULTS

Among 702 included patients, 681 (97.0%) had HbA1c and QFT results. Overall, 54 (7.8%) patients had DM and 235 (33.8%) had pre-DM. LTBI was prevalent in 31.3% of the refugees. LTBI prevalence was significantly higher (P < 0.01) among patients with DM (43.4%) and pre-DM (39.1%) than in those without DM (25.9%). Refugees with DM (adjusted OR [aOR] 2.3, 95%CI 1.2-4.5) and pre-DM (aOR 1.7, 95%CI 1.1-2.4) were more likely to have LTBI than those without DM.

CONCLUSION

Refugees with DM or pre-DM from high TB burden countries were more likely to have LTBI than those without DM. Dysglycemia may impair the immune defenses involved in preventing Mycobacterium tuberculosis infection.

Improving clinical and translational research training: a qualitative evaluation of the Atlanta Clinical and Translational Science Institute KL2-mentored research scholars program

A major impediment to improving the health of communities is the lack of qualified clinical and translational research (CTR) investigators. To address this workforce shortage, the National Institutes of Health (NIH) developed mechanisms to enhance the career development of CTR physician, PhD, and other doctoral junior faculty scientists including the CTR-focused K12 program and, subsequently, the KL2-mentored CTR career development program supported through the Clinical and Translational Science Awards (CTSAs). Our evaluation explores the impact of the K12/KL2 program embedded within the Atlanta Clinical and Translational Science Institute (ACTSI), a consortium linking Emory University, Morehouse School of Medicine and the Georgia Institute of Technology. We conducted qualitative interviews with program participants to evaluate the impact of the program on career development and collected data on traditional metrics (number of grants, publications). 46 combined K12/KL2 scholars were supported between 2002 and 2016. 30 (65%) of the 46 K12/KL2 scholars are women; 24 (52%) of the trainees are minorities, including 10 (22%) scholars who are members of an underrepresented minority group. Scholars reported increased research skills, strong mentorship experiences, and positive impact on their career trajectory. Among the 43 scholars who have completed the program, 39 (91%) remain engaged in CTR and received over $89 000 000 as principal investigators on federally funded awards. The K12/KL2 funding provided the training and protected time for successful career development of CTR scientists. These data highlight the need for continued support for CTR training programs for junior faculty.

Point-of-Care Testing for Cryptococcal Disease Among Hospitalized Human Immunodeficiency Virus-Infected Adults in Ethiopia

In a cross-sectional study among hospitalized human immunodeficiency virus (HIV)-infected patients in Ethiopia, we sought to determine the rates and predictors of cryptococcal disease and evaluate the test performance of a recently introduced point-of-care test for Cryptococcus neoformans detection in various biological samples. We tested serum, urine, and fingerstick blood samples from each patient with a cryptococcal antigen lateral flow assay (CRAG LFA; Immuno Mycologic Inc., Norman, OK). Cerebrospinal fluid was collected at the discretion of the treating physician. Logistic regression was used to identify risk factors for a positive test result. Agreement between different sample types was also assessed. Among 198 hospitalized HIV-infected patients with a median CD4 count of 93 cells/mm³, 18 patients (9.1%) had a positive serum CRAG LFA. Of these, 16 (8.1%) had confirmed cryptococcal meningitis (CM), all of whom had a positive fingerstick blood LFA result. There was a very high agreement between CRAG LFA tests in serum and fingerstick blood samples (κ = 0.97, 95% confidence interval [CI] = 0.91-1.00); this was higher than that between serum and urine samples (κ = 0.76, 95% CI = 0.58-0.93). A CD4 count < 100 cells/mm³ was significantly associated with a positive CRAG LFA. The absence of fever, headache, meningismus, and neck stiffness had a negative predictive value of 100% for CM. In addition to finding high rates of cryptococcal disease, our study demonstrated that the use of the LFA on fingerstick whole blood is less invasive, and an effective method for CM case finding among hospitalized patients with HIV.

Intensified tuberculosis case finding among HIV-infected persons using a WHO symptom screen and Xpert(®) MTB/RIF

SETTING

Human immunodeficiency virus (HIV) clinic in Addis Ababa, Ethiopia. The World Health Organization (WHO) recommends active tuberculosis (TB) case-finding among people living with HIV (PLHIV) in high-burden settings.

OBJECTIVE

To evaluate the effectiveness of combining a WHO-recommended symptom screen and the Xpert(®) MTB/RIF test to enhance TB case finding.

DESIGN

In this cross-sectional study, PLHIV were screened for TB using a WHO-recommended symptom-based algorithm (cough, fever, night sweats, weight loss). Those with a positive symptom screen (⩾1 symptom) underwent diagnostic testing with smear microscopy, culture, and Xpert.

RESULTS

Of 828 PLHIV (89% on antiretroviral therapy), 321 (39%) had a positive symptom screen. In multivariate analysis, an unscheduled clinic visit (aOR 3.78, 95%CI 2.69-5.32), CD4 count <100 cells/μl (aOR 2.62, 95%CI 1.23-5.59) and previous history of TB (aOR 1.62, 95%CI 1.12-2.31) were predictors of a positive symptom screen. Among those with a positive symptom screen, 6% had active pulmonary TB. Smear microscopy sensitivity for TB was poor (30%) compared to culture and Xpert.

CONCLUSIONS

A positive symptom screen was common among PLHIV, creating a substantial laboratory burden. Smear microscopy had poor sensitivity for active TB disease. Given the high rate of positive symptom screen, substantial additional resources are needed to implement intensified TB case finding among PLHIV in high-burden areas.

Knowledge, Attitudes, and Behaviors Regarding Piperacillin-Tazobactam Prescribing Practices: Results From a Multicenter Study

We investigated knowledge, attitudes, and behaviors of prescribers concerning piperacillin-tazobactam use at 4 Emory University-affiliated hospitals. Discussions during focus groups indicated that the participants' perceived knowledge of clinical criteria for appropriate piperacillin-tazobactam use was inadequate. Retrospective review of medical records identified inappropriate practices. These findings have influenced ongoing interventions aimed at optimizing piperacillin-tazobactam use.

Exposure to Tuberculosis among Newborns in a Nursery: Decision Analysis for Initiation of Prophylaxis

Objective.

Newborns in a hospital nursery were exposed to a mother whose sputum was direct-smear negative for acid-fast bacilli but culture positive for Mycobacterium tuberculosis. Given the low risk for exposure, the high susceptibility of infants to M. tuberculosis infection, and the possibility of hepatotoxicity due to isoniazid therapy, a decision analysis model was used to determine whether administration of isoniazid prophylaxis against tuberculosis is preferable to no administration of prophylaxis.

Design.

A decision analysis tree was constructed with software, using probabilities from the literature and costs from local health facilities. The expected values for each strategy were obtained, and sensitivity analyses were performed.

Results.

For the strategy in which prophylaxis was administered under direct observation (DO), the probability for survival was 0.999980. For the strategy in which no prophylaxis was administered, the probability of survival was 0.999950, which corresponds to 3 more deaths per 100,000 patients than with the DO prophylaxis strategy. The incremental cost-effectiveness of the DO prophylaxis strategy was $21,710,000 per death prevented. Sensitivity analysis for survival showed that the DO prophylaxis strategy was preferable to the strategy in which no prophylaxis is given if the probability of infection was >0.0002, the probability of tuberculous disease in an infected infant who did not receive prophylaxis was greater than 0.12, the probability of dying from tuberculosis was greater than 0.025, the probability of hepatotoxicity was less than 0.004, and the probability of dying from hepatotoxicity was less than 0.04. For the strategy in which prophylaxis was administered under non-DO conditions (ie, by parents), the incremental cost-effectiveness was $929,500 per death prevented, which is approximately 5% of the incremental cost-effectiveness of the DO prophylaxis strategy.

Conclusion.

This model provides a structure for determining the preferable prophylaxis strategies for different risks of exposure to tuberculosis in a nursery. Administration of prophylaxis is preferable to no administration of prophylaxis, unless the probability of infection is extremely low.

Diabetes Reduces the Rate of Sputum Culture Conversion in Patients With Newly Diagnosed Multidrug-Resistant Tuberculosis

Background.  Diabetes is a risk factor for active tuberculosis (TB), but little is known about the relationship between diabetes and multidrug-resistant (MDR) TB. We aimed to assess risk factors for primary MDR TB, including diabetes, and determine whether diabetes reduced the rate of sputum culture conversion among patients with MDR TB. Methods.  From 2011 to 2014, we conducted a cohort study at the National Center for Tuberculosis and Lung Diseases in Tbilisi, Georgia. Adult (≥35 years) patients with primary TB were eligible. Multidrug-resistant TB was defined as resistance to at least rifampicin and isoniazid. Patients with capillary glycosylated hemoglobin (HbA1c) ≥ 6.5% or previous diagnosis were defined to have diabetes. Polytomous regression was used to estimate the association of patient characteristics with drug resistance. Cox regression was used to compare rates of sputum culture conversion in patients with and without diabetes. Results.  Among 318 patients with TB, 268 had drug-susceptibility test (DST) results. Among patients with DST results, 19.4% (52 of 268) had primary MDR TB and 13.4% (36 of 268) had diabetes. In multivariable analyses, diabetes (adjusted odds ratio [aOR], 2.51; 95% confidence interval [CI], 1.00-6.31) and lower socioeconomic status (aOR, 3.51; 95% CI, 1.56-8.20) were associated with primary MDR TB. Among patients with primary MDR TB, 44 (84.6%) converted sputum cultures to negative. The rate of sputum culture conversion was lower among patients with diabetes (adjusted hazard ratio [aHR], 0.34; 95% CI, .13-.87) and among smokers (aHR, 0.16; 95% CI, .04-.61). Conclusions.  We found diabetes was associated with an increased risk of primary MDR TB; both diabetes and smoking were associated with a longer time to sputum culture conversion.

Diabetes mellitus is associated with cavities, smear grade, and multidrug-resistant tuberculosis in Georgia

SETTING

National tuberculosis (TB) treatment facility in the country of Georgia.

OBJECTIVE

To determine the prevalence of diabetes mellitus (DM) and pre-DM among patients with TB using glycosylated-hemoglobin (HbA1c), and to estimate the association between DM and clinical characteristics and response to anti-tuberculosis treatment.

DESIGN

A cohort study was conducted from 2011 to 2014 at the National Centre for TB and Lung Disease in Tbilisi. Patients aged ⩾ 35 years with pulmonary TB were included. HbA1c was used to define DM (⩾ 6.5%), pre-DM (⩾ 5.7-6.4%), and no DM (<5.7%). Interviews and medical chart abstraction were performed. Regression analyses estimated associations between DM and 1) baseline TB characteristics and 2) anti-tuberculosis treatment outcomes.

RESULTS

A total of 318 newly diagnosed patients with TB were enrolled. The prevalence of DM and pre-DM was 11.6% and 16.4%, respectively. In multivariable analyses, patients with TB-DM had more cavitation (adjusted OR [aOR] 2.26), higher smear grade (aOR 2.37), and more multidrug-resistant TB (MDR-TB) (aOR 2.27) than patients without DM. The risk of poor anti-tuberculosis treatment outcomes was similar among patients with and those without DM (28.1% vs. 23.6%).

CONCLUSION

DM and pre-DM were common among adults with newly diagnosed pulmonary TB in Tbilisi, Georgia, and DM was associated with more clinical symptoms, and MDR-TB, at presentation.

Contacts of retreatment tuberculosis cases with a prior poor treatment outcome are at increased risk of latent tuberculosis infection

OBJECTIVES

To estimate the prevalence of and risk factors for latent tuberculosis infection (LTBI) among contacts of index patients with tuberculosis (TB) with a prior history of active TB disease and TB treatment (retreatment cases).

METHODS

A cross-sectional population-based study was conducted using data from the national TB contact surveillance program in the country of Georgia. Contacts of retreatment cases were investigated and tuberculin skin testing was offered. Bivariate and multivariable analyses were performed to calculate odds ratios (OR) and 95% confidence intervals for risk of LTBI among contacts.

RESULTS

The prevalence of LTBI was significantly higher among contacts whose index TB patient had had a prior unfavorable treatment outcome compared to those who had had a favorable outcome (OR 3.14). Contacts whose index TB case had previously failed therapy (OR 6.43), was lost to follow-up (OR 5.63), or had completed treatment (OR 3.33) had a significantly higher prevalence of LTBI compared to contacts of previously cured TB cases.

CONCLUSIONS

Among contacts of active TB retreatment cases, the risk of LTBI was related to the outcome of the index case's previous TB treatment. Efforts aimed at reducing treatment loss to follow-up should be emphasized to enhance TB control efforts and may also decrease LTBI and active TB among contacts.

Macronutrient intake and body composition changes during anti-tuberculosis therapy in adults

BACKGROUND

Malnutrition is common in patients with active tuberculosis (TB), yet little information is available on serial dietary intake or body composition in TB disease.

OBJECTIVE

To evaluate macronutrient intake and body composition in individuals with newly diagnosed TB over time.

DESIGN

Adults with active pulmonary TB (n = 191; 23 with multidrug resistant TB (MDR-TB) and 36 culture-negative household contacts (controls) enrolled in a clinical trial of high-dose cholecalciferol (vitamin D3) were studied. Macronutrient intake was determined at baseline, 8 and 16 weeks. Serial body composition was assessed by body mass index (BMI; kg/m(2)) and bioelectrical impedance analysis (BIA) to estimate fat mass and fat-free mass. Descriptive statistics, repeated measures ANOVA for changes over time and linear regression were used.

RESULTS

At baseline, mean daily energy, protein, fat and carbohydrate (CHO) intakes were significantly higher, and body weight, BMI, fat-free mass and fat mass were significantly lower, between TB subjects and controls. These remained significant after adjusting for age, gender, employment status and smoking. In all TB subjects, baseline mean daily intakes of energy, fat and protein were adequate when compared to the US Dietary Reference Intakes and protein significantly increased over time (p < 0.0001). Body weight, BMI, and fat and fat-free mass increased over time. MDR-TB patients exhibited lower body weight and fat-free mass over time, despite similar daily intake of kcal, protein, and fat.

CONCLUSIONS

Macronutrient intake was higher in TB patients than controls, but TB-induced wasting was evident. As macronutrient intake of TB subjects increased over time, there was a parallel increase in BMI, while body composition proportions were maintained. However, individuals with MDR-TB demonstrated concomitantly decreased body weight and fat-free mass over time versus drug-sensitive TB patients, despite increased macronutrient intake. Thus, MDR-TB appears to blunt anabolism to macronutrient intake, likely reflecting the catabolic effects of TB.

Acquired Drug Resistance in Mycobacterium tuberculosis and Poor Outcomes among Patients with Multidrug-Resistant Tuberculosis

Acquired drug resistance is common and an impediment to successful treatment outcomes.

Rates and risk factors for acquired drug resistance and association with outcomes among patients with multidrug-resistant tuberculosis (MDR TB) are not well defined. In an MDR TB cohort from the country of Georgia, drug susceptibility testing for second-line drugs (SLDs) was performed at baseline and every third month. Acquired resistance was defined as any SLD whose status changed from susceptible at baseline to resistant at follow-up. Among 141 patients, acquired resistance in Mycobacterium tuberculosis was observed in 19 (14%); prevalence was 9.1% for ofloxacin and 9.8% for capreomycin or kanamycin. Baseline cavitary disease and resistance to >6 drugs were associated with acquired resistance. Patients with M. tuberculosis that had acquired resistance were at significantly increased risk for poor treatment outcome compared with patients without these isolates (89% vs. 36%; p<0.01). Acquired resistance occurs commonly among patients with MDR TB and impedes successful treatment outcomes.

High-dose vitamin D3 in adults with pulmonary tuberculosis: a double-blind randomized controlled trial

BACKGROUND

Tuberculosis, including multidrug-resistant tuberculosis (MDR-TB), is a major global health problem. Individuals with tuberculosis disease commonly exhibit vitamin D deficiency, which may adversely affect immunity and the response to therapy.

OBJECTIVE

We determined whether adjunctive high-dose vitamin D3 supplementation improves outcomes in individuals with pulmonary tuberculosis disease.

DESIGN

The study was a double-blind, randomized, placebo-controlled, intent-to-treat trial in 199 individuals with pulmonary tuberculosis disease in Tbilisi, Georgia. Subjects were randomly assigned to receive oral vitamin D3 [50,000 IUs (1.25 mg) thrice weekly for 8 wk and 50,000 IU every other week for 8 wk] or a placebo concomitant with standard first-line antituberculosis drugs. The primary outcome was the time for the conversion of a Mycobacterium tuberculosis (Mtb) sputum culture to negative.

RESULTS

Baseline characteristics between groups were similar. Most subjects (74%) were vitamin D deficient (plasma 25-hydroxyvitamin D [25(OH)D] concentration <50 nmol/L). With vitamin D3, plasma 25(OH)D concentrations peaked at ∼250 nmol/L by 8 wk and decreased to ∼125 nmol/L at week 16. Adverse events and plasma calcium concentrations were similar between groups. In 192 subjects with culture-confirmed tuberculosis, an adjusted efficacy analysis showed similar median culture-conversion times between vitamin D3 and placebo groups [29 and 27 d, respectively; HR: 0.86; 95% CI: 0.63, 1.18; P = 0.33). Eight-week culture-conversion rates were also similar (84.0% and 82.1% for vitamin D3 and placebo, respectively; P = 0.99).

CONCLUSION

A high-dose vitamin D3 regimen safely corrected vitamin D deficiency but did not improve the rate of sputum Mtb clearance over 16 wk in this pulmonary tuberculosis cohort. This trial was registered at clinicaltrials.gov at NCT00918086.

Latent tuberculous infection in the United States and Canada: who completes treatment and why?

OBJECTIVES

To assess latent tuberculous infection (LTBI) treatment completion rates in a large prospective US/Canada multisite cohort and identify associated risk factors.

METHODS

This prospective cohort study assessed factors associated with LTBI treatment completion through interviews with persons who initiated treatment at 12 sites. Interviews were conducted at treatment initiation and completion/cessation. Participants received usual care according to each clinic's procedure. Multivariable models were constructed based on stepwise assessment of potential predictors and interactions.

RESULTS

Of 1515 participants initiating LTBI treatment, 1323 had information available on treatment completion; 617 (46.6%) completed treatment. Baseline predictors of completion included male sex, foreign birth, not thinking it would be a problem to take anti-tuberculosis medication, and having health insurance. Participants in stable housing who received monthly appointment reminders were more likely to complete treatment than those without stable housing or without monthly reminders. End-of-treatment predictors of non-completion included severe symptoms and the inconvenience of clinic/pharmacy schedules, barriers to care and changes of residence. Common reasons for treatment non-completion were patient concerns about tolerability/toxicity, appointment conflicts, low prioritization of TB, and forgetfulness.

CONCLUSIONS

Less than half of treatment initiators completed treatment in our multisite study. Addressing tangible issues such as not having health insurance, toxicity concerns, and clinic accessibility could help to improve treatment completion rates.

Knowledge, attitudes, and practices regarding cervical cancer and screening among Ethiopian health care workers

BACKGROUND

Though cervical cancer incidence has dramatically decreased in resource rich regions due to the implementation of universal screening programs, it remains one of the most common cancers affecting women worldwide and has one of the highest mortality rates. The vast majority of cervical cancer-related deaths are among women that have never been screened. Prior to implementation of a screening program in Addis Ababa University-affiliated hospitals in Ethiopia, a survey was conducted to assess knowledge of cervical cancer etiology, risk factors, and screening, as well as attitudes and practices regarding cervical cancer screening among women's health care providers.

METHODS

Between February and March 2012 an anonymous, self-administered survey to assess knowledge, attitudes, and practices related to cervical cancer and its prevention was distributed to 334 health care providers at three government hospitals in Addis Ababa, Ethiopia and three Family Guidance Association clinics in Awassa, Adama, and Bahir Dar. Data were analyzed using SPSS software and chi-square test was used to test differences in knowledge, attitudes, and practices across provider type.

RESULTS

Overall knowledge surrounding cervical cancer was high, although awareness of etiology and risk factors was low among nurses and midwives. Providers had no experience performing cervical cancer screening on a routine basis with <40% having performed any type of cervical cancer screening. Reported barriers to performing screening were lack of training (52%) and resources (53%); however the majority (97%) of providers indicated cervical cancer screening is an essential part of women's health care.

CONCLUSION

There is a clear need among women's health care providers for education regarding cervical cancer etiology, risk factors and for training in low-tech, low-cost screening methods. Meeting these needs and improving the infrastructure necessary to implement appropriate screening programs is essential to reduce the burden of cervical cancer in Ethiopia.

A comparison of the Xpert(®) MTB/RIF and GenoType(®) MTBDRplus assays in Georgia

Few studies have directly compared the performance of rapid molecular diagnostic tests for tuberculosis (TB). We found that the commercially available molecular diagnostic tests Xpert(®) MTB/RIF and GenoType(®) MTBDRplus both provided timely and accurate results compared to conventional phenotypic tests in detecting TB and rifampicin resistance.

Tobacco smoking and tuberculosis treatment outcomes: a prospective cohort study in Georgia

OBJECTIVE

To assess the effect of tobacco smoking on the outcome of tuberculosis treatment in Tbilisi, Georgia.

METHODS

We conducted a prospective cohort study of adults with laboratory-confirmed tuberculosis from May 2011 to November 2013. History of tobacco smoking was collected using a standardized questionnaire adapted from the global adult tobacco survey. We considered tuberculosis therapy to have a poor outcome if participants defaulted, failed treatment or died. We used multivariable regressions to estimate the risk of a poor treatment outcome.

FINDINGS

Of the 591 tuberculosis patients enrolled, 188 (31.8%) were past smokers and 271 (45.9%) were current smokers. Ninety (33.2%) of the current smokers and 24 (18.2%) of the participants who had never smoked had previously been treated for tuberculosis (P < 0.01). Treatment outcome data were available for 524 of the participants, of whom 128 (24.4%) - including 80 (32.9%) of the 243 current smokers and 21 (17.2%) of the 122 individuals who had never smoked - had a poor treatment outcome. Compared with those who had never smoked, current smokers had an increased risk of poor treatment outcome (adjusted relative risk, aRR: 1.70; 95% confidence interval, CI: 1.00-2.90). Those who had ceased smoking more than two months before enrolment did not have such an increased risk (aRR: 1.01; 95% CI: 0.51-1.99).

CONCLUSION

There is a high prevalence of smoking among patients with tuberculosis in Georgia and smoking increases the risk of a poor treatment outcome.

A Multicenter Study on Optimizing Piperacillin-Tazobactam Use: Lessons on Why Interventions Fail

We examined interventions to optimize piperacillin-tazobactam use at 4 hospitals. Interventions for rotating house staff did not affect use. We could target empiric therapy in only 35% of cases. Because prescribing practices seemed to be institution specific, interventions should address attitudes of local prescribers. Interventions should target empiric therapy and ordering of appropriate cultures.

Colonization With Multidrug-Resistant Organisms in Evacuees After Hurricane Katrina

After Hurricane Katrina, 50 patients were evacuated to Grady Memorial Hospital in Atlanta, Georgia, with limited medical records. The infection control department ordered contact precautions for 16 Patients. Surveillance cultures performed on admission identified colonization with multidrug-resistant (MDR) bacteria in 9 patients (18%). Presence of a wound was the strongest predictor for MDR colonization. More data are needed to reliably predict MDR bacterial colonization.

High utility of contact investigation for latent and active tuberculosis case detection among the contacts: a retrospective cohort study in Tbilisi, Georgia, 2010-2011

SETTING

The study was conducted at the National Center for Tuberculosis and Lung Diseases (NCTBLD) in Tbilisi, Georgia.

OBJECTIVE

To assess the utility of contact investigation for tuberculosis (TB) case detection. We also assessed the prevalence and risk factors for active TB disease and latent TB infection (LTBI) among contacts of active pulmonary TB cases.

DESIGN

A retrospective cohort study was conducted among the contacts of active pulmonary TB cases registered in 2010-2011 at the NCTBLD in Tbilisi, Georgia. Contacts of active TB patients were investigated according to an "invitation model": they were referred to the NCTBLD by the index case; were queried about clinical symptoms suggestive of active TB disease; tuberculin skin testing and chest radiographs were performed. Demographic, laboratory, and clinical data of TB patients and their contacts were abstracted from existing records up to February 2013.

RESULTS

869 contacts of 396 index cases were enrolled in the study; a median of 2 contacts were referred per index case. Among the 869 contacts, 47 (5.4%) were found to have or developed active TB disease: 30 (63.8%) were diagnosed with TB during the baseline period (co-prevalent cases) and 17 (36.2%) developed active TB disease during the follow-up period (mean follow up of 21 months) (incident TB cases). The incidence rate of active TB disease among contacts was 1126.0 per 100,000 person years (95% CI 655.7-1802.0 per 100,000 person-years). Among the 402 contacts who had a tuberculin skin test (TST) performed, 52.7% (95% CI 47.7-57.7%) had LTBI.

CONCLUSIONS

A high prevalence of LTBI and active TB disease was found among the contacts of TB cases in Tbilisi, Georgia. Our findings demonstrated that an "invitation" model of contact investigation was an effective method of case detection. Therefore, contact investigation should be scaled up in Georgia.

Plasma metabolomics in human pulmonary tuberculosis disease: a pilot study

We aimed to characterize metabolites during tuberculosis (TB) disease and identify new pathophysiologic pathways involved in infection as well as biomarkers of TB onset, progression and resolution. Such data may inform development of new anti-tuberculosis drugs. Plasma samples from adults with newly diagnosed pulmonary TB disease and their matched, asymptomatic, sputum culture-negative household contacts were analyzed using liquid chromatography high-resolution mass spectrometry (LC-MS) to identify metabolites. Statistical and bioinformatics methods were used to select accurate mass/charge (m/z) ions that were significantly different between the two groups at a false discovery rate (FDR) of q<0.05. Two-way hierarchical cluster analysis (HCA) was used to identify clusters of ions contributing to separation of cases and controls, and metabolomics databases were used to match these ions to known metabolites. Identity of specific D-series resolvins, glutamate and Mycobacterium tuberculosis (Mtb)-derived trehalose-6-mycolate was confirmed using LC-MS/MS analysis. Over 23,000 metabolites were detected in untargeted metabolomic analysis and 61 metabolites were significantly different between the two groups. HCA revealed 8 metabolite clusters containing metabolites largely upregulated in patients with TB disease, including anti-TB drugs, glutamate, choline derivatives, Mycobacterium tuberculosis-derived cell wall glycolipids (trehalose-6-mycolate and phosphatidylinositol) and pro-resolving lipid mediators of inflammation, known to stimulate resolution, efferocytosis and microbial killing. The resolvins were confirmed to be RvD1, aspirin-triggered RvD1, and RvD2. This study shows that high-resolution metabolomic analysis can differentiate patients with active TB disease from their asymptomatic household contacts. Specific metabolites upregulated in the plasma of patients with active TB disease, including Mtb-derived glycolipids and resolvins, have potential as biomarkers and may reveal pathways involved in TB disease pathogenesis and resolution.

Performance of the MTBDRsl assay in Georgia

SETTING

The country of Georgia has a high burden of multi- (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB).

OBJECTIVE

To assess the performance of the GenoType® MTBDRsl assay in the detection of resistance to kanamycin (KM), capreomycin (CPM) and ofloxacin (OFX), and of XDR-TB.

DESIGN

Consecutive acid-fast bacilli smear-positive sputum specimens identified as MDR-TB using the MTBDRplus test were evaluated with the MTBDRsl assay and conventional second-line drug susceptibility testing (DST).

RESULTS

Among 159 specimens, amplification was adequate in 154 (97%), including 9 of 9 culture-negative and 2 of 3 contaminated specimens. Second-line DST revealed that 17 (12%) Mycobacterium tuberculosis isolates were XDR-TB. Compared to DST, the MTBDRsl had 41% sensitivity and 98% specificity in detecting XDR-TB and 81% sensitivity and 99% specificity in detecting OFX resistance. Sensitivity was low in detecting resistance to KM (29%) and CPM (57%), while specificity was respectively 99% and 94%. Median times from sputum collection to second-line DST and MTBDRsl results were 70-104 vs. 10 days.

CONCLUSION

Although the MTBDRsl assay had a rapid turnaround time, detection of second-line drug resistance was poor compared to DST. Further genetic mutations associated with resistance to second-line drugs should be included in the assay to improve test performance and clinical utility.